Waste water installation with purification device

ABSTRACT

In waste water installations, the amount of falling rainwater which increases as a result of heavy precipitations is diverted into lakes and waterways in order to relieve the sewage treatment plant. In order to remove the impurities carried along with said rainwater, the water is purified using a purification device. A retaining element is disposed behind the purification device in the direction of flow. Said element is at least partially detachably connected to a base surface ( 15 ) and can be used to release the through-flow in the region of the base surface ( 15 ) of the purification device in an intermittent manner. Preferably, the retaining element ( 3 ) is pivotable around an axis ( 7 ).

[0001] The invention is relative to a waste-water installation with aninflow side and an outflow side and a clearing device in accordance withthe generic part of claim 1 arranged between them. Such waste-waterinstallations are used to drain off the increased amount of rainwaterthat accumulates during rather heavy precipitations since it can nolonger be managed, e.g., by a sewage treatment plant. However, theincreased amount of accumulating rainwater is mixed with contaminatedwater, so that it is contaminated with suspended material, e.g., piecesof wood, sand, paper or plastic foils. These contaminants [impurities]are removed or retained from the rainwater diverted, e.g., into a bodyof water, by such waste-water installations by means of a cleaningdevice, e.g. a sieve [screen] rake. The above-mentioned cleaning deviceis arranged between the inflow area of the waste water and the outflowarea from which the rainwater drained off for removal of the load[relief] is conducted away. Such a device is known from WO 94/07585.

[0002] The device shown in this document comprises an intermediate wallbetween the inflow side and the outflow side on which wall a cleaningdevice in the form of a sieve rake is arranged. In addition to theaction of the intermediate wall, a damming element inclined to thevertical plate is provided in the direction of flow behind the sieverake in order to increase the damming [dammed, retention, water-head,water-pressure, backwater] volume. It should help to even out theflowthrough rate of the water through the sieve rake and obtain a moreuniform distribution of pressure over the entire surface of the sieverake. However, the device shown has the disadvantage that in particularsuspended material and sinking [settling] material such as, e.g., sandcan not overcome the inclined damming element so that they remain in thearea of the sieve rake and cause problems there, especially for the rakecleaner. The remaining sinking material causes increased wear betweenthe sieve rake and the rake cleaner. In addition, the damming elementdoes increase the retention capacity of the waste-water installation,but if the damming element is flooded the damming element forms athrottling device so that the flowthrough amount through the rake isreduced and there is the danger that the sieve rake is flooded above itsupper edge, as a result of which unpurified water is removed.

[0003] The present invention has the problem of avoiding the citeddisadvantages of the known waste-water installations and also not tohinder the flowthrough through the cleaning device of the waste-waterinstallation in spite of the elevation of the damming volume. Theinvention solves this problem with the features of claim 1.

[0004] The fact that the damming element is connected at least in apartially detachable manner in the area of the bottom area with thisbottom area makes it possible to produce an interval between the bottomarea and the damming element so that water can flow through in thisarea. As a consequence thereof, a flow is produced in the area of thebottom area or the rate of flow rises there significantly so thatsettled sinking material can be removed. This material thus also passesout of the area of the cleaning device, where it can result in increasedwear or problems in the cleaning device. All this is made possible bythe fact that the damming element is movably supported and therefore atleast a periodic release of the flowthrough in the area of the bottomarea can be made possible. If the damming element is designed so that itcommunicates in the area of the bottom area in a detachable manner withthe bottom area, a damming up of water in the waste-water installationcan be achieved with the damming element in accordance with theinvention even at a relatively low water element and it can be assuredat the same time that the disadvantages of a backup, e.g., the settling[depositing] of sinking material or the reduction of the cross sectionof the flow are eliminated with the device of the present invention.

[0005] It is especially advantageous is the damming element is designedin a multipartite fashion, which makes it possible, e.g., to design onlya narrow area of the damming element to be movable, especially in thearea of the bottom area, whereas the remaining part of the dammingelement is installed in a fixed manner. This can make a good damming up[backup] possible and at the same time the device can be designed to beeconomical. Even though the damming element can be designed to besubstantially simple therewith, it can it can be designed to be stableand light at the same time and also to be fixed in a simple manner inthe waste-water installation.

[0006] The dividing of the damming element into several individualcomponents can take place not only in a horizontal direction but alsovertically.

[0007] In an advantageous further development of the invention thedamming element is shiftably mounted, as a result of which it can befavorably designed in accordance with space conditions or for utilizingspecial driving means of the damming element. In an especially favorableembodiment of the invention the damming element is mounted so that itcan pivot about a shaft [axis]. This makes an especially reliablefastening possible and brings it about at the same time that therequirements of the invention are made possible with the aid of a simpleform of movement. Moreover, it is possible, given a pivotable support,to make the drive for adjusting the damming element possible simply inthat the water backing up on the damming element presses on a surface ofthe damming element and as a result moves the latter in a manner inaccordance with the invention.

[0008] The designing of the shaft [axis] as a substantially horizontalshaft or, depending on the design of the bottom area, also as a shaftrunning parallel to the bottom area is especially advantageous. Theadvantages of the invention can be achieved in particular in a simplemanner in that the swivel axis is at an interval from the bottom area sothat as a result of the pivoting movement about this swivel [pivoting]axis the area of the bottom area can be freed from the damming element,during which the flow pressure of the dammed-up water, or its flow freesthe bottom area from sinking material in accordance with the invention.

[0009] In an especially advantageous further development of theinvention the damming element is designed in a multipartite manner. Onedivision of the damming element can take place in a horizontal directionas well as in a vertical direction. A division of the damming elementinto partial surfaces makes it possible that, e.g., only the area in thevicinity of the bottom area is dammed up by a movable damming elementwhereas the area above it is dammed up by a damming element mounted in afixed manner. As a result, it is economical to manufacture the dammingelement with its damming action. In order to make a cleaning of sinkingmaterial possible, it is not necessary to design the entire dammingelement to be movable but it is frequently sufficient to design only thearea of the damming element between the swivel axis and the bottom areato be movable. In an advantageous alternative embodiment the swivel axisabout which the damming element is moveably mounted can be arranged onthe side edge of the damming element, that is, substantially running ina vertical direction. As a result, the movement of the damming elementtakes place similar to that of a door or flap. This embodiment can beespecially advantageous for the maintenance and cleaning of the cleaningdevice of the waste-water installation.

[0010] The advantageous design of the waste-water installation in whichthe damming element is arranged at an interval from the cleaning devicebrings it about that sufficient space for a freedom of movement for themoving of the damming element is available. This has the additionaladvantage that a settling of sinking material can take place in the areabetween the cleaning device and the damming element so that the sinkingmaterial passes reliably out of the area of the cleaning device andtherewith out of the area in which wear is possible. A collection areafor the sinking material is created by this design.

[0011] In an especially advantageous embodiment the damming element ispivoted about a swivel axis during the movement of the damming element,during which the part of the damming element located under the swivelaxis moves in the direction of the cleaning device. This brings it aboutthat the water backed up at least to the level of the swivel axispresses in such a manner on the damming element that the latter isreliably sealed and that in this manner a sufficient damming up of thewater in the waste-water installation is achieved. A movement away fromthe cleaning element is also advantageously possible if a sufficientseal is assured elsewhere.

[0012] In an especially advantageous embodiment of the invention thedamming element is constructed from a metallic material and designed asa flap. A flap can be opened in an especially simple manner by theflowing medium so that the action of the movable damming element,namely, e.g., the increased flowthrough or the cleaning of sinkingmaterial is made possible in an especially simple manner. The design ofthe waste-water installation in accordance with the invention and with acollection area between the cleaning device and the damming elementbrings it about in a reliable manner that the sinking material andsuspended material can be deposited in a sufficient amount before theycan result in problems in the cleaning device. Accordingly, the dammingelement advantageously also comprises a cleaning position that isspecially set up so that in particular the collection area receives anespecially vigorous flowthrough, independently of the other flowthroughproperties of the waste-water installation, and is quite thoroughlycleaned as a result thereof.

[0013] In an especially advantageous further development of theinvention a control device is provided that controls the dammingelement, e.g., via a drive device in such a manner that a reduction ofthe damming action of the damming element is achieved as desired as afunction of the level of the accumulating amount of water. It can beprovided that the control device also comprises sensors that makepossible a regulating of the liquid level and of the flowthrough rate ofthe backed-up water.

[0014] In an advantageous further development of the invention thedamming element is equipped with a guide device that makes it possibleto hold the damming element in a position, by utilizing the propertiesof the dammed-up or already flowing water, in which position it ispivoted about the swivel axis so that the cleaning action and thecontrol of the flowthrough can be carried out. Thus, no additionalprovision of foreign energy or of control devices or of regulatingdevices need be made. The guide device can be designed with advantage,e.g., as a type of carrier surface that makes possible a lifting of thepivoted damming element so that its intrinsic weight, e.g., is not usedto pivot the damming element back and thus interrupt the flowthroughbetween the damming device and the bottom area.

[0015] An especially advantageous embodiment of the invention providesthat the damming element is arranged at least partially in the plane ofthe bottom area or below it. This brings it about that the part of thedamming element, e.g., a partial surface, that is movably mountedremoves the water already in the area of the bottom area and thatdeposited sinking material need only traverse a short path for removal.It is especially simple to fasten and support a shaft in the area of thebottom area because the bottom area forms a stabile support for theshaft of the pivotably mounted damming element. In an advantageousembodiment of the invention the shaft runs substantially verticallyrelative to the cleaning device. This embodiment facilitates thepivoting of the damming element and reduces the influence of the flow onthe damming element.

[0016] The invention is explained in the following using the drawings.

[0017]FIG. 1 shows a diagrammatic view of a waste-water installation inaccordance with the invention in section.

[0018]FIG. 2 shows a partial view similar to FIG. 1.

[0019]FIG. 3 shows a view similar to FIG. 2 with a different dammingelement.

[0020]FIG. 4 shows a sectional view of a shiftably supported dammingelement.

[0021]FIG. 5 shows a top view onto a cleaning device with a dammingflap.

[0022]FIG. 6 shows a diagrammatic view similar to FIG. 1 with a controldevice.

[0023]FIG. 7 shows a diagrammatic view similar to FIG. 1 with a dammingelement whose shaft runs in the bottom area.

[0024]FIG. 8 shows a top view onto the bottom area with the movableparts of the damming element arranged in it.

[0025]FIG. 1 shows a first exemplary embodiment of waste-waterinstallation 1 in accordance with the invention in a schematic,sectional view. Waste-water installation 1 comprises inflow side 11 andoutflow side 12 that are arranged in a so-called relief basin. Inflowside 11 and outflow side 12 are separated from one another byintermediate wall 14. A cleaning device 2 is arranged on the top ofintermediate wall 14 on its bottom area 15. Inflow side 11 is connectedto an inflow line (not shown) via which rainwater is delivered, e.g.,during heavy rain events to waste-water installation 1. The rainwater ismixed thereby without separation with normal waste water and deliveredto waste-water installation 1. In the normal instance the water suppliedto inflow side 11, that is, during dry periods and light rainfalls, isconducted out of inflow side 11 to waste-water installation 1 via aconduit connection (not shown) into a sewage treatment plant. Inflowside 11 of relief basin 13 can additionally communicate with a retentionbasin that assures an at least partial intermediate storage for theincreased accumulation of water to be cleaned so that as much of thewater as possible supplied via the inflow side of waste-waterinstallation 1 can be delivered to the sewage treatment plant. Theretention basin also assures that the accumulation of water to becleaned in the sewage treatment plant is stretched out in time.

[0026] However, if the amount of accumulating water is so great, e.g.,during a heavy rain event, that it can not be received by the retentionbasin and by [from] inflow side 11 of waste-water installation 1, theliquid level in inflow side 11 rises at first until it reaches level N1of bottom area 15 of intermediate wall 14. A further rise of the liquidon inflow side 11 would, without further measures, have the result thatwater would pass by the sewage treatment plant into the area of outflowside 12 of waste-water installation 1, from where this water is thendischarged, e.g., into a natural body of water.

[0027] However, in order to avoid that non-cleaned water passes, e.g.,into a natural body of water, cleaning device 2 is arranged betweeninflow side 11 and outflow side 12. This cleaning device is designed inthe exemplary embodiment of FIG. 1 as sieve rake 22, that is capable ina known manner, with rake rods 23 running in parallel and horizontallyarranged, of retaining dirt components out of the water flowing throughit. In order that sieve rake does not clog up, cleaning device 2comprises rake cleaner 24, shown only schematically in FIG. 1, with theaid of which the intermediate spaces between rake rods 23 arecontinuously cleaned and dirt components deposited in front of the rakeare removed.

[0028] In one exemplary embodiment, as shown in FIG. 1, the dirt removedby rake cleaner 24 from the sieve rake is returned into the waste waterlocated in inflow side 11 since if the water in waste-water installation1 recedes, this dirt can then be removed by the normal cleaning by thesewage treatment plant. In addition to cleaning device 2, it is alsoknown in the state of the art that a damming element 3 can be providedin the direction of flowthrough after sieve rake 22, that is, betweencleaning device 2 and outflow side 12 which damming element is supposedto increase the amount of water retained at first by further damming sothat as little water as possible is removed from a cleaning action bythe sewage treatment plant.

[0029]FIG. 1 shows a damming element 3 in accordance with the presentinvention. Damming element 3 is capable of damming the backup level ofthe liquid in inflow side 11 above level N1 backed up by intermediatewall 14 up to level N2 located above level N1. Without the use of adamming element in accordance with the invention, still no water wouldpass onto outflow side 12 at damming level N2, that corresponds to thelevel of damming element 3 in FIG. 1. However, according to the presentinvention damming element 3 is mounted so that it can move in such amanner that it executes, effected by the forces of the backup pressureby liquid level N2, a pivoting motion about shaft 7. During this timepartial surface 32 of damming element 3 pivots in the direction of arrowP, that is, away from cleaning device 2, thus freeing the area betweenshaft 7 and bottom area 15. The open position of damming element 3 isshown in dotted lines in FIG. 1. The folding back in accordance with theinvention of partial surface 32 of damming element 3 brings it aboutthat in the area of bottom area 15 water flows over bottom area 15 at ahigh rate, thus cleaning bottom area 15. The water flowing underneathshaft 7 passes to outflow side 12 of waste-water installation 1 andleaves it in the direction of, e.g., a natural body of water. Thedesigning of damming element 3 as a multipartite damming element bringsit about that the part of the damming element located above shaft 7continues to dam the water located on the inflow side. As a result, thewater on inflow side 11 can continue to be retained for the most part,and nevertheless, due to the designing in accordance with the inventionof damming element 3 a current can be produced in the area of bottomarea 15 that cleans bottom area 15 of deposits such as, e.g., sand, sothat these deposits do not cause any problems in the area of the sieverake, e.g., during the cooperation of sieve rake 22 with rack cleaner24.

[0030] Basically, the attempt is made to operate the waste-waterinstallation in such a manner that all the accumulating water is removedto the extent possible by the conduit line (not shown) from the area ofinflow side 11 in order to clean it in a sewage treatment plant.Consequently, damming element 3 and/or its partial surface 32 is/areadvantageously designed so that an opening of the damming element onlytakes place when an overflowing of damming element 3 on its upper edge36 takes place in any case by the great accumulation of water on inflowside 11. In order to bring this about, partial surface 32 of dammingelement 3 can be pre-tensioned with a spring (not shown) in such amanner that the water pressure only succeeds in pivoting partial surface32 about shaft 7 when a sufficient dammed pressure of the water ispresent, that is, when the liquid level N2 has been practically reached.

[0031] In addition to loading damming element 3 with a spring, it isalso possible to assure by skillful distributions of mass on partialsurface 32 of damming element 3, which partial surface is located undershaft 7, that a moment is exerted on this partial surface 32 so that itrests in a sealing manner on stop 16. A further elevation of the waterlevel on inflow side 11, e.g., up to over level N2 would then becapable, given the appropriate shaping of the forces acting on partialsurface 32, to pivot this partial surface and free therewith theflowthrough of water.

[0032] Damming element 3 shown in FIG. 1 is designed in the area of itspartial surface 32 as a flap that can pivot about shaft 7 and with theaid of which the effects intended by the invention can be achieved. Inaddition to a flap pivotable about shaft 7, it is just as possible, inan especially advantageous manner, to design partial surface 32 as anelastically deformable structural component, e.g., in the form of asealing lip capable by virtue of its deformation of effecting therelease of the flowthrough of the liquid in the area of bottom area 15.Given a rather low liquid pressure on the elastically deformablestructural component, its deformational return forces bring it aboutthat it rests in a sealing manner on stop 16 of waste-water installation1 so that this installation can retain a rather large [greater] amountof water on inflow side 11 with the aid of its damming element 3 beforethis water must be discharged into, e.g., a natural body of water.

[0033] The impurities of the water that accumulate in waste-waterinstallation 1 and pass with the rainwater and the waste water mixedwith it into the area of inflow side 11 are retained in a known mannerby cleaning device 2 when the water in waste-water installation 1 passesfrom inflow side 11 directly to outflow side 12. Cleaning device 2 isdesigned as sieve rake 22 and consists substantially of rake rodsarranged superposed horizontally, e.g., with a slot width between therake rods of 3 mm to 11 mm. Sieve rake 22 comprises rake cleaner 24 forkeeping the intermediate spaces between the individual rake rods freefrom the dirt particles pressed on the inflow side of the rake in thearea of the rake rods by the flow of the liquid. This rake cleaner isdesigned to be movable and is arranged on the side of sieve rake 22facing outflow side 12.

[0034] Rake cleaner 24 travels for cleaning along sieve rake 22 andengages thereby with cleaning elements into the intermediate spacesbetween rake rods 23. The intermediate space between rake rods 22 isfilled thereby with cleaning elements 22 of rake cleaner 24 so that dirtcomponents located there, e.g., grains of sand, substantially aggravatethe movement of the rake cleaner and can result in wear to the rake rodsand especially to the cleaning elements of rake cleaner 24, depending ofthe hardness of the dirt components. This is especially critical in thearea of the components of cleaning device 2 located in the vicinity ofbottom area 15. Suspended particles settle with preference on thelatter, especially when the water level on inflow side 11 is onlyslightly higher than level N1 up to a water level in the range of N2,since up to that point no flow can take place in the area betweendamming element 3 and cleaning device 2. Moving rake cleaner 24 back andforth will then always stir up just enough of the sinking material thatits damaging influence can be tolerated since it passes thereby into therange of the rake cleaner.

[0035] In addition to the positive effects of a waste-water installation1 in accordance with the invention as shown in FIG. 1 with its dammingelement 3 in accordance with the invention, the present invention hasthe further advantage that in the event of a heavy rain with a largeaccumulation of dirty water on inflow side 11, the flowthrough of theoncoming water through sieve rake 22 is distributed over its entiresurface if in such an event damming element 3 frees the flowthrough,even if only partially as in the exemplary embodiment of FIG. 1, and toa particular extent if a damming element like the one shown in FIG. 2 isused. This brings it about that the liquid flowing through the rake isdistributed over its entire height so that the passage rate is uniformlythe same over the entire height of cleaning device 2. This achieves anespecially advantageous action of cleaning device 2.

[0036]FIG. 2 shows a schematic view of a section through waste-waterinstallation 1 similar to FIG. 1; however, only the area of theintermediate wall, bottom area 15 and a partial area of cleaning device2 are shown. Sieve rake 22 arranged on intermediate wall 14, which rakeis also associated with a rake cleaner 24, is followed by dammingelement 3 in flowthrough direction F. Damming element 3 is designed inthe exemplary embodiment of FIG. 2 as damming flap 36 that can pivotabout shaft 7. Damming flap 36 is shown in its position that it assumeswhen liquid flows in flowthrough direction F, that is, a state in whichdamming element 3 has changed following the damming pressure of thebacked-up water from a closed position into a flowthrough position. Theclosed position of damming flap 36 is sketched with an interrupted linefrom which it is clear that damming element 3 consists in the exemplarydesign of FIG. 2 of two partial surfaces 32 separated from one anotherby shaft 7. Partial surface 32 shown above shaft 7 has a greater heightand therewith also greater surface than partial surface 32 arrangedbelow shaft 7. This geometric shape has the effect that at a liquidlevel with level N21 the forces act on the two partial surfaces 32 insuch a manner that a torque acts around shaft 7 so that partial surface32 located beneath shaft 7 is pressed away from sieve rake 22 and restssealingly on stop 16 formed in the area of bottom area 15. If the liquidrises further, the force acting on upper partial surface 32 becomesgreater and greater until it is capable of rotating damming flap 36clockwise about shaft 7. As a result thereof, damming element 3 of FIG.2 frees the flowthrough in a practically unhindered manner so thatpractically no more damming action is effected.

[0037] In order that damming flap 36 retains its open position, as shownin FIG. 2 with an uninterrupted line, in such as instance, even if thewater level drops, the damming flap comprises guide device 35 on itspartial surface arranged below shaft 7 which guide device directs theforce of the liquid flowing by in such a manner onto damming flap 36that the latter remains in the open position even if the liquid levelhas already dropped down to approximately the level of shaft 7.

[0038]FIG. 3 shows a diagrammatic view similar to that of FIG. 2 butwith a damming element 3 that consists of two partial surfaces 32pivotably mounted about horizontal shaft 7 running between them. Inorder to form an effective damming element several of flap elements 37shown in FIG. 3 are arranged along the back side of cleaning device 2.The individual flap elements forming damming element 3 comprise anarticulating lever (not shown) with which they can be pivoted, e.g., viaa control rod from the open position into the closed position. The driveenergy necessary for this can be generated, e.g., by a suitable powertransfer means via the backed-up water or via the flowing water.However, it is also advantageously possible in addition to move flapelements 37 from the open position into the closed position and viceversa via, e.g., a hydraulic system or an electromotor. This design ofthe damming element has the advantage that only relatively low forcesare required to move the flap elements, independently of the waterlevel.

[0039]FIG. 4 shows another advantageous exemplary embodiment of thepresent invention in which a multipartite damming element 3 is alsoarranged in the direction of the flowthrough of the water behindcleaning device 2. Damming element 3 consists of partial surface 32installed in a fixed manner in waste-water installation 1 and of partialsurface 320 also movably arranged transversely to the direction offlowthrough of the flowing medium. In the exemplary embodiment of FIG. 4movably arranged partial surface 320 is arranged on partial surface 32arranged in a fixed manner in waste-water installation 1 on the sidefacing away from cleaning device 2. An arrangement of movable partialsurface 320 in the direction of flow in front or after the fixed part ofdamming element 3 makes no difference in principle but rather is afunction of the practical situation such as, e.g., sliding surfaces andguide surfaces for movable partial surface 320. Just as in the case ofdamming element 3 in the exemplary embodiment of FIG. 3 a drive deviceoperating with foreign energy should preferably be provided for shiftingmovable partial surface 320. However, it is also conceivable to performthe opening and closing of movable partial surface 320 via the backed-upor flowing water with the aid of suitable means, e.g., floats orbaffles.

[0040] In addition to an embodiment of the invention like the one shownin FIG. 4 it is also conceivable to arrange the entire damming element 3movably in the waste-water installation so that the flowthrough of waterbelow the damming element is released by a shift in the verticaldirection. Such a design makes it possible not only to realize a smallslot or interval between damming element 3 and bottom area 15 that isespecially suited for generating high flow rates in the area of bottomarea 15 and therewith removing the deposited suspended material andsinking material in an especially reliable manner, but it is alsoadditionally possible therewith to move the damming element verticallyin such a manner that the entire surface of cleaning device 2 is freedfor an unimpeded passage of the liquid. This mode of operation shouldparticularly be provided if there is a danger that cleaning device 2 isinundated as a consequence of a large amount of accumulating water.

[0041]FIG. 5 shows another embodiment of the invention in which dammingelement 3 can be opened in a pivoting motion similar to a door aboutvertical shaft 7. FIG. 5 shows a top view of a diagrammatic view of acleaning device 2 built into the wall of a waste-water installation 1.Damming element 3 frees the passage of the water in the area of bottomarea 15 in that it is pivoted substantially in the direction of flow Saway from cleaning device 2. The pivoting takes place via drive device 8that can be designed, e.g., as a hydraulic piston. This embodiment of amovable damming element 3 in accordance with the invention has theadvantage that damming element 3 can be moved away rapidly and in asimple manner, e.g., for maintenance, so that sieve rake 22 is readilyaccessible from both sides.

[0042]FIG. 6 shows a section of a diagrammatic view similar to that ofFIG. 1. Damming element 3 is divided into partial surface 32 installedin a fixed manner and into movable partial surface 320. Damming element3 is also arranged in the direction of flow S behind cleaning device 2.Movable partial surface 320 of damming element 3 closes off the areabetween bottom area 15 and stationary partial surface 32 of dammingelement 3 in its closed position. To this end movable partial surface320 is loaded by drive device 8 that presses movable partial surface 320onto bottom area 15 so that a seal is created. It is provided foropening and closing movable partial surface 320 that drive device 8 issupplied via control device 81 with control signals and driving energy.Control device 81 is connected via control leads 82 to sensors 83 withwhose aid the level of the liquid in front of damming element 3 can bemeasured. The measuring takes place in a known manner, e.g., bymeasuring the pressure or optically. It is therefore possible with theaid of this advantageous design of the invention to open or closemovable partial surface 320 as a function of the level of the backed-upwater.

[0043] In addition, an opening and closing of damming element 3 can beregulated with the aid of control device 81 as a function of timeintervals. This makes it possible to assure at regular intervals thatbottom area 15 and therewith cleaning device 2 and its rake cleaner areregularly rinsed and washed in such a manner that deposited sinkingmaterial is removed from their area. It is, of course, a prerequisitefor this that the amount of water in inflow side 11 has reached asufficient dammed height [level] that a flow of water over bottom area15 is possible at all. It is, of course, also possible to combine asensor control and a time control or to make a cleaning of bottom area15 possible by a manual intervention.

[0044]FIG. 7 shows a diagrammatic view of a waste-water installation inaccordance with the invention similar to that of FIG. 1. In thewaste-water installation of FIG. 7 damming element 3 is also designed ina multipartite manner in which damming element 3 consists of twoseparate structural components 33 of which one, the pivotably mountedone, is arranged in the plane of bottom area 15 so that it can pivotabout shaft 7. The movable partial surface 320 is designed so that inits closed state it rests practically in a plane with bottom area 15. Asthe dammed pressure of the water backing up on damming element 3increases, movable partial surface 320 of damming element 3 begins topivot in the direction of arrow P downward about shaft 7 and opens theflowthrough of the water underneath the stationary partial surface ofdamming element 3 in the direction of arrow W. In its closed positionmovable partial surface 320 is held by elastic elements (not shown).Their pressure force is overcome by a certain dammed level of the waterin front of damming element 3 so that the flowthrough takes place in thedirection of arrow W. Intermediate wall 14 is designed in acorresponding manner so that it can receive movable partial surface 320.

[0045] Another embodiment is shown with an interrupted line in whichmovable partial surface 320 is arranged substantially below bottom area15 even though its shaft 7 also runs substantially at the level ofbottom area 15.

[0046]FIG. 8 shows a section of a device 1 in accordance with theinvention in a top view onto bottom area 15 with movable partialsurfaces 320 of damming element 3 arranged in it, which damming elementconsists of several partial surfaces 32. The uppermost rake rod 23 ofsieve rake 22 can be recognized in the top view as well as the top viewonto movable partial surfaces 320 of damming element 3, whose top viewis represented by two parallel lines. The top view onto outflow side 12is recognizable to the right of damming element 3. Movable partialsurface 320 shown above is presented in its closed position whereas themovable partial surface 320 shown below is pivoted about shaft 7 so thatit is shown in its half-open position. Intermediate wall 14 is providedin a manner similar to that in FIG. 7 with a perforation through whichthe water passes in the direction of arrow W into outflow side 12 ofwaste-water installation 1. As is clear from FIG. 8, especially on themovable partial surface 320 shown at the bottom, shaft 7 is arrangedsubstantially vertically relative to cleaning device 2.

[0047] In addition to the cited embodiment other cleaning devices thatare not based on a principle of a sieve rake can be used just as well ina waste-water installation in accordance with the invention. Theinvention makes it possible, independently of the embodiment of theindividual elements, to intervene in a waste-water installation in sucha manner that the disadvantages of the state of the art are avoided bymaking possible a flowthrough of water from inflow side 11 to outflowside 12.

1. A waste-water installation with an inflow side for contaminated waterand with an outflow side for cleaned water and with a cleaning deviceextending between them from a bottom area for retaining or separatingimpurities delivered on the inflow side and with a damming elementarranged in the direction of flow after the cleaning device in the areaof the bottom area, characterized in that the damming element (3)communicates in an at least partially detachable [releasable] manner inthe area of the bottom area (15) with the latter and that the dammingelement (3) is movably supported or elastically deformable for theperiodic release of the flowthrough in the area of the bottom area (15).2. The waste-water installation according to claim 1, characterized inthat the damming element (3) is designed to be multipartite.
 3. Thewaste-water installation according to claim 1 or 2, characterized inthat the damming element (3) is supported in such a manner that it canshift.
 4. The waste-water installation according to claim 1 or 2,characterized in that the damming element (3) is pivotably supportedabout a shaft (7).
 5. The waste-water installation according to claim 3,characterized in that the shaft (7) runs substantially horizontally orparallel to the bottom area (15) and at an interval from the bottom area(15).
 6. The waste-water installation according to one or more of claims2 to 5, characterized in that the damming element (3) is divided intopartial surfaces (32) arranged in different planes.
 7. The waste-waterinstallation according to one or more of claims 1 to 6, characterized inthat the damming element (3) is divided into partial surfaces (32)separated by a shaft (7).
 8. The waste-water installation according toclaim 7, characterized in that the partial surfaces (32) are formed byseparate structural components (33) of the damming element (3).
 9. Thewaste-water installation according to one or more of claims 4 to 8,characterized in that the shaft (7) runs on a side edge (34) of thedamming element (3).
 10. The waste-water installation according to oneor more of claims 5 to 9, characterized in that the damming element (3)is arranged at an interval from the cleaning device (2).
 11. Thewaste-water installation according to one or more of claims 5 to 10,characterized in that the area of the damming element (3) located underthe shaft (7) reduces the interval to the cleaning device (2) when thedamming element (3) is pivoted.
 12. The waste-water installationaccording to one or more of claims 1 to 11, characterized in that thedamming element (3) is constructed as a flap consisting of metallicmaterial.
 13. The waste-water installation according to one or more ofclaims 1 to 12, characterized in that a collection area (21) for sinkingmaterial or suspended material is arranged between the cleaning device(2) and the damming element (3).
 14. The waste-water installationaccording to one or more of claims 1 to 13, characterized in that thedamming element (3) comprises a cleaning position for cleaning thecollection area (21).
 15. The waste-water installation according to oneor more of claims 1 to 14, characterized in that a control device (81)is provided for controlling the damming element (3).
 16. The waste-waterinstallation according to one or more of claims 1 to 15, characterizedin that the damming element (3) comprises a guide device (35) influencedby the flowing water for retaining the position of the damming element(3) pivoted about the shaft (7).
 17. The waste-water installationaccording to one or more of claims 2 to 16, characterized in that thedamming element (3) is arranged in part in the plane of the bottom area(15).
 18. The waste-water installation according to claim 17,characterized in that the damming element (3) is supported in such amanner that it can pivot about a shaft (7) running in the plane of thebottom area (15) or below the bottom area (15).
 19. The waste-waterinstallation according to claim 17 or 18, characterized in that theshaft (7) runs substantially vertically to the cleaning device (20.